Yahoo, which has bought dozens of companies since Marissa Mayer took over as CEO, put the brakes on in the first quarter.

The Sunnyvale company said in its earnings announcement on Tuesday that it spent only $22 million on eight deals in the first quarter, down from $60 million in the fourth quarter of last year and $163 million in the third quarter.

The Q2 2013 quarter was thrown way off by the outlier acquisition of Tumblr for about $970 million.

Maybe it's just an annual New Year's diet for Yahoo. It only did $10 million worth of M&A in last year's first quarter, so on a year-to-year basis it is actually up better than 100 percent.

A qualifier in the drop in spending is that it's not clear exactly how Yahoo is coming up with its net cost numbers.

Another is that it is about to get an estimated $10 billion from a divestiture of part of its stake in Alibaba when that Chinese Internet giant does an IPO in the U.S. There will be pressure to turn some of that back to shareholders who have been buying Yahoo stock mainly on the basis of its 24 percent stake in Alibaba.

Meaningful acquisitions that would put Yahoo into growing new businesses could run into the billions of dollars. Some areas that have been speculated on by analysts have been in the so-called "sharing economy" companies like Uber and Airbnb, streaming video and music, and online learning.